1. Field of the Invention
This invention relates to electronic component packaging means for packing surface-mounted-type electronic components (hereinafter referred to as "electronic components"), and a supply mechanism for and a method of supplying electronic components by using the packaging means. More particularly, this invention relates to packaging means for packing electronic components for storage and transportation as well as for supplying electronic components to a mounting head of an automatic electronic component mounting apparatus when the mounting head is to mount electronic components on printed circuit boards, and a supply mechanism for and a method of supplying electronic components to the mounting head by using the packaging means.
2. Description of the Prior Art
Hitherto, an automatic electronic component supplying mechanism having a bulk-type storage cassette is widely used as means to feed surface-mounted-type electronic components to a mounting head of an automatic electronic component mounting apparatus, since a plurality of surface-mounted-type electronic components can be stored in bulk in the bulk-type storage cassette and the electronic components received in the bulk-type storage cassette can be fed to the mounting head one by one.
This kind of bulk-type storage cassette is disclosed in Japanese patent application which was laid open to public inspection under provisional publication No. 280129/1987.
The storage cassette comprises a body having a storage chamber formed in its interior for storing a plurality of electronic components in bulk, an electronic component passageway formed at a bottom of the storage chamber, and an outlet formed at a terminal end of the passageway. In order to permit the electronic components received within the storage chamber to move downward by gravity, the interior of the storage chamber is formed into a substantially mortar-shape or funnel-shape. Alternatively, the body of the storage cassette is obliquely arranged in a manner that the storage chamber is inclined. The electronic components received within the storage chamber are adapted to move downward by gravity and travel on the passageway to be discharged one by one out of the body through the outlet.
In the conventional electronic component supply mechanism having the storage cassette, the storage cassette is arranged with the outlet thereof being located at a lower and side position, so that when a mounting head is moved downward with respect to the outlet in order to directly receive an electronic component discharged from the outlet, the storage cassette will interfere with the downward movement of the mounting head. Also, there is a possibility that the mounting head will fail to receive an electronic component discharged from the outlet. In order to avoid such trouble, a suction head or receiving base, which is adapted to directly receive an electronic component discharged from the outlet, is employed. The suction head or receiving base is arranged close to the outlet. The suction head or receiving base which receives the electronic component is adapted to be moved laterally away from the outlet. When the suction head or receiving base is moved laterally and arrives at a predetermined position where vertical movement of the mounting head is not interrupted by the storage cassette, the mounting head is moved downward with respect to the electronic component received by the suction head or receiving base and takes up the electronic component from the suction head or receiving base to mount the electronic component on a printed circuit board.
In the conventional supply mechanism, the outlet of the storage cassette is located at a lower and side position as described above. Therefore, if an X-Y table on which a printed circuit board is carried is arranged on the side of the storage cassette which is opposite to the side of the storage cassette on which the suction head or receiving base is arranged, this will require the mounting head to move in several directions. More particularly, in addition to the vertical movement, the mounting head after taking up an electronic component from the suction head or receiving base has to move round about the storage cassette or has to go over the storage cassette in order to mount the electronic component on the printed circuit board carried on the X-Y table. This is undesirable for high-speed mounting of electronic components. In order to eliminate such inconvenience, the X-Y table on which a printed circuit board is carried is forced to be arranged on the side of the storage cassette only, on which the suction head or receiving base is arranged. Thus, the arranging position of the X-Y table is restricted. In addition, the conventional supply mechanism includes the suction head or receiving base as an indispensable part thereof, so that the supply mechanism is complex in construction and high in manufacturing cost.
One example of packaging means, which is adapted to pack electronic components for storage and transportation and is also adapted to be used as an electronic component supply source, is disclosed in Japanese utility model application (in the name of TDK Corporation) which was laid open to public inspection under provisional publication No. 111682/1990 on Sep. 6, 1990.
The packaging means disclosed in the above utility model application comprises a substantially disk-like body. The body comprises a substantially disk-like base portion and a substantially disk-like cover portion. The disk-like base portion has a spiral groove formed in one surface thereof, an outlet formed at a side portion thereof as a continuation of an outermost portion of the spiral groove, and a plurality of air-intakes, the air-intakes being formed at respective circular portions of the spiral groove to communicate between the spiral groove and the exterior of the disk-like base portion. A plurality of electronic components are received in a row in the spiral groove of the disk-like base portion. The disk-like cover portion is mounted on a spirally grooved surface of the disk-like base portion.
When the electronic component packaging means is used as an electronic component supply source, the electronic component packaging means is adapted to be supported on a base of an electronic component supply mechanism so as to stand on the base with the outlet being located at a lower and side position. Also, when the packaging means is supported on the base, the air-intakes of the packaging means are adapted to be connected through coupling means to an air supply source which is adapted to intermittently feed air. Air intermittently supplied from the air supply source flows into the spiral groove through the air-intakes, whereby the electronic components received in the spiral groove are moved toward the outlet along the spiral groove and then discharged one by one from the outlet. An electronic component discharged from the outlet of the packaging means is received by receiver means which is arranged close to the outlet of the packaging means and adapted to be moved laterally. The receiver means which receives an electronic component discharged from the outlet is laterally moved away from the outlet to a position below a waiting position of a mounting head of an electronic component mounting apparatus. Then, the mounting head is moved downwardly with respect to the receiver means to hold, via suction, the electronic component received by the receiver means. The mounting head holding the electronic component is moved upwardly and then moved toward a printed circuit board to mount the electronic component on the printed circuit board. The packaging means is preferred in terms of storage and transportation because it is compact and has the spiral groove permitting a plurality of electronic components to be received therein.
As described above, the packaging means is designed so that the outlet formed at the side of the body of the packaging means is located at a lower and side position when the packaging means is supported on the base of the electronic component supply mechanism. Therefore, if an X-Y table on which a printed circuit board is carried is arranged on the side of the packaging means, which is opposite to the side of the packaging means on which the receiver means is arranged, this will require the mounting head to move in several directions as just the mounting head in the above-described conventional electronic component supply mechanism is required to do so. In order to eliminate such inconvenience, the X-Y table is forced to be arranged on the side of the packaging means only on which the receiver means is arranged. Thus, the arranging position of the X-Y table is restricted. Furthermore, the electronic component supply mechanism which is adapted to supply electronic components using the packaging means includes the receiver means as an indispensable part thereof, so that the supply mechanism is complex in construction and high in manufacturing cost.
As described above, when the packaging means is used as an electronic component supply source, it is adapted to be supported on the base of the electronic component supply mechanism with the body standing on the base. The electronic components contained in the body of the packaging means are moved toward the outlet along the spiral groove by air intermittently fed into the spiral groove through the air-intakes. The intermittent feeding of air into the body through the air-intakes is adapted to be carried out each time one electronic component is discharged out of the body through the outlet. When air is fed into the spiral groove through the air-intakes, the electronic components received in the spiral groove are moved toward the outlet along the spiral groove while colliding with one another. Also, when the feeding of air into the spiral groove through the air-intakes is stopped, electronic components, which have been moved to upper regions of respective circular portions of the spiral groove of the packaging means standing on the base of the electronic component supply mechanism, are moved toward lower regions of the respective circular portions of the spiral groove by gravity while colliding with one another. Such collision of the electronic components with one another will be brought about each time the feeding of air is carried out and stopped. Repeated collision of the electronic components with one another, may result in the electronic components being damaged and/or may result in characteristics of the electronic components deteriorating. Therefore, in the conventional packaging means, it is necessary to reduce possibilities that electronic components contained in the packaging means will collide with one another during the movements of the electronic components along the spiral groove.